--- name: cost-tracker version: 1.0.0 author: Polycat tags: [cost, tokens, budget, llm, monitoring, api] license: MIT platform: universal description: Track LLM API spend per session and task. Estimate token usage across providers. Warn before you blow your budget. --- # 💰 Cost Tracker > **Compatible with Claude Code, Codex CLI, Cursor, Windsurf, and any SKILL.md-compatible agent.** Track what your AI sessions actually cost. Estimate token usage, cumulative spend, and warn you before you hit budget thresholds — across OpenAI, Anthropic, Google, and other major providers. --- ## Triggers Activate this skill when: - User asks "how much has this session cost?" - User asks "what's my token usage?" - User sets a session budget ("keep this under $2") - User wants a cost estimate before a large task - Cumulative session spend needs tracking - "track my costs", "budget check", "token count", "how much am I spending" --- ## Pricing Reference (update as models change) Use these rates to estimate costs. All prices are per 1M tokens (input / output). ### Anthropic | Model | Input | Output | |-------|-------|--------| | claude-opus-4 | $15.00 | $75.00 | | claude-sonnet-4 | $3.00 | $15.00 | | claude-haiku-4 | $0.80 | $4.00 | | claude-opus-3 | $15.00 | $75.00 | | claude-sonnet-3.5 | $3.00 | $15.00 | | claude-haiku-3.5 | $0.80 | $4.00 | ### OpenAI | Model | Input | Output | |-------|-------|--------| | gpt-4o | $2.50 | $10.00 | | gpt-4o-mini | $0.15 | $0.60 | | gpt-4-turbo | $10.00 | $30.00 | | gpt-4 | $30.00 | $60.00 | | gpt-3.5-turbo | $0.50 | $1.50 | | o1 | $15.00 | $60.00 | | o1-mini | $3.00 | $12.00 | | o3-mini | $1.10 | $4.40 | ### Google | Model | Input | Output | |-------|-------|--------| | gemini-2.0-flash | $0.075 | $0.30 | | gemini-2.0-pro | $1.25 | $5.00 | | gemini-1.5-pro | $1.25 | $5.00 | | gemini-1.5-flash | $0.075 | $0.30 | ### Other | Model | Input | Output | |-------|-------|--------| | mistral-large | $3.00 | $9.00 | | mistral-small | $0.20 | $0.60 | | llama-3.3-70b (Groq) | $0.59 | $0.79 | | deepseek-r1 | $0.55 | $2.19 | > ⚠ī¸ Prices change frequently. Always verify at the provider's pricing page before making financial decisions. --- ## How It Works ### Session Tracking When activated, maintain a running cost ledger in the conversation context: ``` SESSION COST LEDGER =================== Model: claude-sonnet-4 Started: [timestamp] Turn | Input tok | Output tok | Cost ------|-----------|------------|------ 1 | 2,340 | 450 | $0.0134 2 | 4,120 | 890 | $0.0259 3 | 1,870 | 340 | $0.0107 ------|-----------|------------|------ Total | 8,330 | 1,680 | $0.0500 Budget: $2.00 | Used: $0.05 (2.5%) | Remaining: $1.95 ``` ### Token Estimation When you can't read token counts directly from the API response, estimate: **Quick estimates (rough, for planning):** - 1 token ≈ 4 characters of English text - 1 token ≈ ž of a word - Code is denser: 1 token ≈ 3 characters - 1 page of plain text ≈ 500–750 tokens - 1,000-word article ≈ 1,300–1,500 tokens **File size estimates:** - Small file (<50 lines): ~500–1,000 tokens - Medium file (50–200 lines): ~1,000–4,000 tokens - Large file (200–500 lines): ~4,000–10,000 tokens - Full codebase context: count with `wc -c` then divide by 4 **Pre-task estimate command:** ```bash # Estimate tokens in a file wc -c myfile.py | awk '{printf "~%d tokens\n", $1/4}' # Estimate tokens in entire codebase find . -name "*.py" -o -name "*.ts" -o -name "*.js" | xargs wc -c 2>/dev/null | tail -1 | awk '{printf "~%d tokens (input)\n", $1/4}' # Count words as rough proxy wc -w myfile.txt | awk '{printf "~%d tokens\n", $1*1.3}' ``` ### Budget Warnings Issue warnings at these thresholds: - **50%** of budget: ℹī¸ Heads up — halfway through budget - **80%** of budget: ⚠ī¸ Approaching limit — consider wrapping up - **95%** of budget: 🚨 Budget nearly exhausted — stop or expand ### Cost Estimation Before Large Tasks Before any task involving large files or long conversations, estimate upfront: ``` 📊 PRE-TASK ESTIMATE ==================== Task: Refactor entire codebase Files to read: 23 files (~180,000 chars) Estimated input: ~45,000 tokens Expected output: ~8,000 tokens (code changes + explanation) Model: claude-sonnet-4 Estimated cost: $0.255 Input: 45,000 × $3.00/M = $0.135 Output: 8,000 × $15.00/M = $0.120 Proceed? This is ~13% of your $2.00 budget. ``` --- ## Output Format ### Quick status (inline, on request) ``` 💰 This session: ~$0.05 (8,330 tokens in / 1,680 out) | Budget: $1.95 remaining ``` ### Full report (on request or at session end) ``` ╔══════════════════════════════════════╗ ║ SESSION COST REPORT ║ ╠══════════════════════════════════════â•Ŗ ║ Model: claude-sonnet-4 ║ ║ Duration: 23 minutes ║ ╠══════════════════════════════════════â•Ŗ ║ INPUT TOKENS ║ ║ Turns: 12 ║ ║ Total tokens: 42,840 ║ ║ Cost: $0.1285 ║ ╠══════════════════════════════════════â•Ŗ ║ OUTPUT TOKENS ║ ║ Total tokens: 8,920 ║ ║ Cost: $0.1338 ║ ╠══════════════════════════════════════â•Ŗ ║ TOTAL COST: $0.2623 ║ ║ Budget used: 13.1% of $2.00 ║ ║ Remaining: $1.74 ║ ╚══════════════════════════════════════╝ ``` --- ## Multi-Provider Session If a session spans multiple models or providers: ``` MULTI-MODEL SESSION SUMMARY ============================ gpt-4o → 12,000 in / 2,400 out → $0.054 claude-haiku-4 → 45,000 in / 8,000 out → $0.068 gemini-flash → 8,000 in / 1,200 out → $0.001 ──────────────────────────────────────────────── TOTAL → 65,000 in / 11,600 out → $0.123 ``` --- ## Common Scenarios ### "How much did that last task cost?" Calculate the tokens in the most recent exchange, apply the current model's rates, and report inline. ### "Estimate the cost of indexing my repo" ```bash find . -type f \( -name "*.py" -o -name "*.ts" -o -name "*.js" -o -name "*.md" \) \ | xargs wc -c 2>/dev/null | tail -1 \ | awk '{ tokens = $1/4 cost_sonnet = (tokens/1000000) * 3.00 cost_haiku = (tokens/1000000) * 0.80 cost_gpt4o = (tokens/1000000) * 2.50 printf "Repo size: ~%.0f tokens\n", tokens printf "claude-sonnet-4: $%.4f\n", cost_sonnet printf "claude-haiku-4: $%.4f\n", cost_haiku printf "gpt-4o: $%.4f\n", cost_gpt4o }' ``` ### "Set a $5 budget for this session" Acknowledge the budget, start tracking, and proactively warn at 50%, 80%, and 95% thresholds. If the budget would be exceeded by a planned task, warn before proceeding. --- ## Notes - Token counts are **estimates** unless the model API returns exact counts in its response metadata - Output tokens are typically 3–10× more expensive per token than input — optimize accordingly - Caching (where available) can reduce input costs by 80–90% for repeated context - Streaming responses don't change token costs — you pay for tokens regardless - System prompts count as input tokens on every turn